1. Field of the Invention
The invention is directed to a method of preparing electronically connected optoelectronic devices such as organic electroluminescent devices and organic photovoltaic devices and to electrically connected devices obtained according to this method.
2. Brief Description of the Prior Art
The past decade has seen an increasing amount of research into the use of organic materials in optoelectronic devices, examples of such devices include organic electroluminescent devices, as disclosed in WO90/13148 and organic photovoltaic devices, as disclosed in U.S. Pat. No. 5,670,791. Both organic electroluminescent devices and organic photovoltaic devices are organic diodes comprising a layer of organic material between two electrodes. Organic electroluminescent devices emit light on the passage of a current between the two electrodes. Organic electroluminescent devices have a wide range of applications in the display industry. Organic photovoltaic devices generate a current between the two electrodes when light is incident upon the device. Organic photovoltaic devices are viewed as a replacement for inorganic silicon solar cells. Advantages associated with the use of organic optoelectronic devices include a greater flexibility in the design of materials and the tailoring of device properties, improved processability and lower cost.
In addition to applications in the field of displays, organic electroluminescent devices have great potential for use in large area lighting applications such as in panel lighting, emergency lighting and advertising. When developing organic electroluminescent devices for use in large area lighting, in addition to the problems which occur in display technology, the skilled person is presented with a range of further problems, in particular how to prepare a large area electroluminescent light source which can be operated at higher voltages, such as at mains voltage and which can be prepared in an efficient manner.
Organic photovoltaic devices have at present been used to generate voltages of around 1V, such low voltages have relatively few practical applications. It is known in the art to connect silicon based photovoltaic cells and dye-sensitised photovoltaic cells in series in order to provide a greater volatge output. A simple and efficient method for the series connection of organic photovoltaic cells would enable higher voltages to be generated and allow organic photovoltaic devices to access a wider range of applications.
The invention is directed to a method of preparing electronically connected optoelectronic devices such as organic electroluminescent devices and organic photovoltaic devices and to electrically connected devices obtained according to this method.